Option to open in browser from modal menu

# Issue details

The option to have Wallabag handle HTTP scheme is useful to save articles without needing to open them in the browser. However, this prevents you from opening links in the browser without manually copying the URL in the browser bar. It would be very helpful to be able to configure a browser inside Wallabag and have a shortcut to open links in that browser/defer to the system app picker.

### Duplicate?
Have you searched the issues of this repository if your issue is already known? yes

### Actual behaviour

The modal menu does not have an option to open in browser. Or it does have one but when you have set Wallabag to be the default browser it is not useful.

### Expected behaviour

The modal menu has a button to open the link in the actual browser.

# Steps to reproduce the issue
1. Set the "Handle HTTP scheme" option in Miscellaneous settings
2. Open any link
3. Try to open it in the browser

# Environment details
- **wallabag app version**: 2.5.1
- **wallabag app installation source** (e.g. Gplay, F-Droid, manual): F-Droid
- **Android OS version**: 13
- **Android ROM** (e.g. stock, LineageOS, SlimRom,…): LineageOS
- **Android hardware**: not relevant
- **wallabag server version**: 2.6.9
- **Do you have Two-Factor-Authentication enabled?**: not relevant

# Your experience with wallabag Android app

Still starting to use it but nice app :)